CHARLOTTE, N.C. -- An appeals court decision this week to stand by an earlier ruling involving bathroom access for a transgender student deals another legal blow to North Carolina's controversial House Bill 2, experts say.

The court's action also appears to coincide with a recent University of North Carolina decision not to enforce HB 2's most controversial provision -- requiring transgender individuals to use the bathrooms that correspond with the gender on their birth certificates.

HB 2 has touched off a searing national debate over transgender protections along with a flurry of lawsuits aimed at upholding or overturning the new law.

One of the complaints -- by the American Civil Liberties Union -- names the University of North Carolina as a defendant. In a filing for the case, UNC President Margaret Spellings said the system's 17 colleges and universities will not be following HB 2 until there's a final decision in the case.

"I have no intent to exercise my authority to promulgate any guidelines or regulations that require that transgender students use the restrooms consistent with their biological sex," Spellings said in a sworn statement.

If any student or employee complains that they have been forced to use a bathroom "inconsistent with their gender identity," Spellings said she would order an investigation to determine if "any violations of the university's nondiscrimination policy and applicable law" has occurred.

Up to now, Spelling has said the university had been caught between the conflicting orders of HB 2 and the federal government, which has sued North Carolina over its new law. Public school districts also have differed on whether they will be following state or federal directives on the bathroom issue. The federal government has said up to $4.5 billion in annual school appropriations could be withheld if North Carolina schools follow HB 2.

Late Tuesday, as expected, the 4th Circuit Court of Appeal in Richmond, Va., refused to reconsider the case of Gavin Grimm, a Virginia transgender student who sued his school district for requiring him to use a special bathroom. Grimm was born female but identifies as a male. The trial judge threw out Grimm's complaint, saying the federal government had overstepped its authority by including transgender rights under its anti-discrimination laws.

In April, a three-judge 4th Circuit panel overturned that decision and ordered the judge to hold a trial on Grimm's complaint. The school system filed an appeal, which the appeals court judges this week declined to hear.

The Virginia school district has one potential move remaining -- to the Supreme Court. But legal experts say it's not clear the schools will file that appeal or that four of the eight justices will agree to hear it.

Law professors Brian Clarke of the Charlotte School of Law and Carl Tobias of the University of Richmond say the Supreme Court traditionally doesn't get involved in legal fights such as HB 2 until rulings from various appeal courts contradict each other -- as was the case in 2014 when the court finally heard arguments over same-sex marriage.

That prospect may only be a few months away. Eleven states have filed suit against the federal government in Texas federal court over President Barack Obama's directive that public school districts uphold transgender bathroom access.

Campbell University Law professor Greg Wallace said politics could decide the HB 2 debate before the Supreme Court intervenes.

"There's no expectation that the Supreme Court will hear the case. The upcoming presidential election may remove the issue if the incoming president changes the Obama administration's policy (on transgender discrimination)," Wallace said.

As of now in North Carolina, the 4th Circuit's ruling in the Virginia case takes precedence. The judges' finding that the federal government can rightfully include transgender protections under the Civil Rights Act "completely undercuts" the lawsuits filed by Gov. Pat McCrory and legislative leaders in support of HB 2, Clarke said. Those complaints accuse the feds of radically reinterpreting discrimination laws.

Wallace, though, said the 4th Circuit's decision only deals with bathrooms. Still to be determined: the public's "competing privacy interests" in locker rooms, showers and other changing facilities, he said.